The leader in this movement of insurrectionary thought was Denis Diderot. Diderot (1713-1784) was born to be an encyclopædist, and a captain of encyclopædists. Force inexhaustible, and inexhaustible willingness to give out force; unappeasable curiosity to know; irresistible impulse to impart knowledge; versatile capacity to do every thing, carried to the verge, if not carried beyond the verge, of incapacity to do any thing thoroughly well; quenchless zeal and quenchless hope; levity enough of temper to keep its subject free from those depressions of spirit and those cares of conscience which weigh and wear on the over-earnest man; abundant physical health,--gifts such as these made up the manifold equipment of Diderot for rowing and steering the gigantic enterprise of the "Encyclopædia" triumphantly to the port of final completion, through many and many a zone of stormy adverse wind and sea, traversed on the way. Diderot produced no signal independent and original work of his own; probably he could not have produced such a work. On the other hand, it is simply just to say that hardly anybody but Diderot could have achieved the "Encyclopædia." That, indeed, may be considered an achievement not more to the glory, than to the shame, of its author; but whatever its true moral character, in whatever proportion shameful or glorious, it is inalienably and peculiarly Diderot's achievement; at least in this sense, that without Diderot the "Encyclopædia" would never have been achieved.